The SelectionRange is the date or dates selected and highlighted on the MonthCalendar control. If only one date is selected, the Start and End property values will be equal. The SelectionRange can be changed by the user clicking a date while dragging the mouse pointer across the desired dates, or you can set the range in code. For example, you might want to have the user enter a date range into two TextBox controls or two DateTimePicker controls and set the SelectionRange based on those dates.

The following example sets the SelectionRange property of a MonthCalendar control based on two dates entered into two TextBox controls when a Button is clicked. This code assumes new instances of a MonthCalendar control, two TextBox controls, and a Button have been created on a Form. You might consider adding code to validate the Text assigned to the text boxes to verify that they contain valid dates.